Rumors, gossip, exclusion. Mean girls have a lot of weapons in their repertoire – here's how to combat all that nastiness.

Step 1No matter how intimidated you may feel on the inside, do your best to exude confidence on the outside. Standing up straight and maintaining eye contact will send the signal that you're not a doormat. Mean girls single out targets they deem weak, but often stay away from confident girls.

Step 2When possible, travel in a group of friends. Mean girls tend to shy away from packs, instead focusing their attention on solo prey.

Step 3Be nice and stay nice. If you're in a class or after-school activity with a mean girl, compliment what she's wearing or nonchalantly offer help with a math problem. If you can get one mean girl on your good side, the rest may fall in line.

Ask a parent or older sibling for advice. Almost everyone has had at least one experience with bullies.

Step 4Mean girls thrive on reactions, so if you're not making any headway, go into "ignore mode" and pretend you're immune to everything they say or do. This will probably only work a few times, though. If the mean girls are really determined, ignoring them is not a long-term solution.

Step 5Confront mean girls using the divide-and-conquer approach. Calmly talk to an influential girl one-on-one, and ask her an up-front question like, "Did I do something that made you mad?" Use "I" statements rather than "you" ones. A mean girl can easily deny anything you say about her, but she'll have a harder time arguing against your personal feelings.

Step 6If the mean girls are relentless, causing you to become depressed or anxious, or threatening to get physical, involve your parents and the school faculty. Though it may not seem like it, popular kids don't actually run the school. Those who do run it can help put any mean girls in their place.